• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.5
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• pp.455-461
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• 2002

limiting nutrients for phytoplankton were determined by dissored inorganic nitrogen/phosphorous (DIN/DIP) in situ and algal bioassay experiment in the Seomjin River estuary during a study period from March 1999 to October 2001. DIN/DIP ranged from 14.7 to 681.1 during the study period. DIN/DIP was over 16 at the upper and middle estuarine region where salinity was lower than 25 psu and chlorophyll a concentration was high, probably indicating P-limitation in this region while the ratio was less than 16 at the high saline (> 25 psu) region, reflecting the supply of DIP from Gwangyang Bay and thereby indicating N-limitation at the lower estuarine region. These results suggested that the spatial distribution of DIN/DIP in the study region was controlled by the high supply of phosphate from Gwangyang Bay, the low input from Seomjin River and the active uptake by phytoplankton within the estuarine system. The bioassay experiments using Skeletonema costatum, Thalaasiosira rotula and in situ phytoplankton assemblage displayed relatively higher growth of phytoplankton in the P-added culture media, indicating P-limitation. This result was well consistent with the spatial distribution of inorganic nutrients. S. costatum showed a rapid adaptation to the low salinity compared to other phytoplankton species. This phenomenon seemed to account for the strong (> $90\%$ in total cell number) S. costatum bloom in autumn in this estuary. Moreover, although phytoplankton growth rate was higher in the P-added culture media at the end of culture experiment of in situ phytoplankton, the fast growth in the trace metal-added media at the beginning of the experiment suggested a possibility of limitation by other micro-nutrients such as trace metal and vitamin etc.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.7 no.2
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• pp.93-100
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• 2009

This study has been carried out to look into the characteristics of an oxidative-dissolution of fission products (FP) co-dissolved with uranium (U) in a $(NH_4)_2CO_3$ carbonate solution. Simulated FP-oxides which contained 12 components have been added to the solution to examine their dissolution characteristics. It is found that $H_2O_2$ is an effective oxidant to minimize the oxidative-dissolution of FP. In the 0.5 M $(NH_4)_2CO_3$-0.5 M $H_2O_2$ solution, some elements such as Re, Te, Cs and Mo seem to be dissolved together with U, while 98${\pm}$2% for Re and Te, 94${\pm}$2% for Cs, and 29${\pm}$2 % for Mo are dissolved for 2 hours. It is revealed that dissolution rates of Re, Te and Cs are high (completely dissolved within 10${\sim}$20 minutes) due to their high solubility in the $(NH_4)_2CO_3$ solution regardless of the addition of $H_2O_2$, and independent of the concentrations of $Na_2CO_3$ and $H_2O_2$. However, the dissolution ratio of Mo seems to be slightly increased with time and about 33 % for 4 hours, indicating a very slow dissolution rate and also independent of the $(NH_4)_2CO_3$ concentration. It is found that the most important factor for the oxidative-dissolution of FP is the pH of the solution and an effective dissolution is achieved at a pH between 9${\sim}$10 in order to minimize the dissolution of FP.

• Clean Technology
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• v.25 no.1
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• pp.81-90
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• 2019

A dielectric barrier discharge (DBD) plasma reactor packed with $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was used for the dry ($CO_2$) reforming of propane (DRP) to improve the production of syngas (a mixture of $H_2$ and CO) and the catalyst stability. The plasma-catalytic DRP was carried out with either thermally or plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst at a $C_3H_8/CO_2$ ratio of 1/3 and a total feed gas flow rate of $300mL\;min^{-1}$. The catalytic activities associated with the DRP were evaluated in the range of $500{\sim}600^{\circ}C$. Following the calcination in ambient air, the ${\gamma}-Al_2O_3$ impregnated with the precursor solution ($Ni(NO_3)_2$ and $Ce(NO_3)_2$) was subjected to reduction in an $H_2/Ar$ atmosphere to prepare $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst. The characteristics of the catalysts were examined using X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectrometry (EDS), temperature programmed reduction ($H_2-TPR$), temperature programmed desorption ($H_2-TPD$, $CO_2-TPD$), temperature programmed oxidation (TPO), and Raman spectroscopy. The investigation revealed that the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst exhibited superior catalytic activity for the production of syngas, compared to the thermally reduced catalyst. Besides, the plasma-reduced $Ni-CeO_2/{\gamma}-Al_2O_3$ catalyst was found to show long-term catalytic stability with respect to coke resistance that is main concern regarding the DRP process.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.303-308
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• 2016

This study was carried out to determine the effects of application levels of fertilizer and sowing methods on yields and nutritive values of Italian ryegrass (IRG) in early spring. Five fertilizer levels were used: Treatment 1, 100-80-80 kg/ha; Treatment 2, 120-100-100 kg/ha; Treatment 3, 140-120-120 kg/ha; Treatment 4, 160-140-140 kg/ha; Treatment 5, 140-120-120 kg/ha of $N-P_2O_5-K_2O$ with silicate fertilizer 200 kg/ha. Dry matter (DM) yield was 8,330 kg/ha in Treatment 5, 7,686 kg/ha in Treatment 4, and 7,347 kg/ha in Treatment 3. There was no significant difference in total digestible nutrients (TDN) content. The content of crude protein was the highest in Treatment 5. Dry matter ratio was the lowest in Treatment 5. In Treatment 3, DM yield was 7,347 kg/ha, when total amounts of fertilizers were applied at one time. However, DM yield was 7,405 kg/ha, when 50% of pre-planting fertilizer and 50% of supplementary fertilizer were applied at different time. There was no significant difference between total application and split application of fertilizers. However, DM yield was 9,469 kg/ha in application treatment with 100 kg/ha of additional urea at three to four leaf stages of IRG. Regarding DM yield by sowing methods of IRG, the following order was found: drill seeding (8,176 kg/ha) > rotary-broadcast seeding-stamping (7,957 kg/ha) > rotary-broadcast seeding (7,810 kg/ha) > broadcast seeding (7,347 kg/ha) > broadcast seeding-rotary (7,034 kg/ha). DM yield (59.57%) was the lowest in broadcast seeding-rotary. Crude protein content was the highest with rotary work but the lowest with broadcast seeding.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.459-468
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• 2004

An experiment was conducted to establish comparison of ventulation efficiency in an enclosed and conventional growing-finishing pig house. The main results of the experiment are as follows : In the established temperature was sustained at the level of summer 24.8${\sim}$29.1$^{\circ}C$, winter 17.9${\sim}$23.1$^{\circ}C$ during the experimental period of enclosed growing-finishing pig house, and conventional growing-finishing pig house was at the lovel of summer 24.7${\sim}$32.3$^{\circ}C$, winter 14.5${\sim}$18.2$^{\circ}C$ during the experimental period respectively. As for the results of dertimental gas(ammonia) concentration ratio analysis, while the conventional pig house sustained of summer 9.3${\sim}$16.9 mg/$\ell$ level, enclosed growing-finishing pig house sustained of summer 7.9${\sim}$16.1 mg/$\ell$, and the latter one is lower than that of the conventional growing-finishing pig house. Air flow rate on the floor level which is the low part of pen and the active area of pigs in the enclosed growing and finishing pig house during winter was measured at 0 to 0.87 m/s at the 0.01 to 2.73 m/s at the maximum ventilation efficiency. As for breeding pigs in summer, the pigs from the conventional pig house weighed 100.2kg, on the other hand, the pigs from enclosed growing-finishing pig house weighed 107.3 kg ; the differnce between the two kinds was about 7 kg. This was because the most adequate environment, which was not influenced by the exterior atmosphere, was offered to the pigs from enclosed growing-finishing pig house, and all of this could reduce pigs stress effectively.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.14 no.2
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• pp.155-160
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• 2011

Purpose: This study was performed to evaluate the role of colonoscopy in children with hematochezia. Methods: We retrospectively reviewed the medical records of 277 children who underwent colonoscopy because of hematochezia between January, 2003 and July, 2010. Results: The mean age of the patients was $6.0{\pm}4.4$ (7 days~17.8 years) years. The male to female ratio was 2.2:1. The duration between the 1st episode of hematochezia and colonoscopy was $4.9{\pm}12.1$ months. Characteristics of hematochezia included red stool (65.1%), blood on wipe (12.8%), bloody toilet (11.9%), and blood dripping (10.2%). The most proximal region of colonoscopic approach was terminal ileum (84.5%), cecum (9.5%), hepatic flexure (2.8%), and splenic flexure (3.2%). Eighty five patients (30.6%) had no specific abnormal findings. Major causes of hematochezia were polyp (26.4%), food protein induced proctocolitis (6.9%), infectious colitis (5.4%), lymphofolliculitis (5.7%), non specific colitis (5.7%), and vascular ectasia (5.1%). The hemorrhagic sites included the rectum (24.0%), rectosigmoid junction (18.1%), sigmoid colon (13.5%), ascending colon (14.2%), transverse colon (11.3%), descending colon (7.8%), cecum (8.1%), and terminal ileum (3.1%). The recurrence rate of hematochezia after colonoscopy was 19.1%. Colonoscopy was performed in 262 patients (94.6%) with conscious sedation. Endoscopic hemostasis was performed in 5 patients. Complications of colonoscopy or sedation were not found. Conclusion: The causes and lesional localization of pediatric hematochezia were diverse. Colonoscopy has an important role in the diagnosis and treatment of hematochezia in children. Total colonoscopy is recommended to detect the cause of hematochezia.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.3
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• pp.157-163
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• 2005

The increasing of greenhouse gases may change agricultural environment. The agronomic productivity will depend upon change of temperature, precipitation, solar radiation and fertilization. Particularly, nitrogen fertilization considerably influences rice productivity and agricultural environments. This experiment was conducted to study transformation of nitrogen and to determine the primary yield components responsible for yield differences in paddy soil. $NH_4-N$ concentration of NPK plot in surface water of paddy soil was $2.07mg\;L^{-1}$ at 5 days after transplanting, and then was decreased sharply due to rice absorption and loss to environment. $NO_3-N$ concentration of NPK plot in surface water was $3.97mg\;L^{-1}$ at 10 days after transplanting. $NO_3-N$ concentration range of CRF plot in surface water was $3-5mg\;L^{-1}$ at 30th after transplanting. The accumulation of $NH_3$ volatilization in NPK plot was $22.39kg\;ha^{-1}$, which accounted for 20% of N fertilizer applied but using of CRF fertilizer can reduce $NH_3$ volatilization by 67% in paddy soil. Use efficiency of N fertilizer was not different between CRF70% and CRF100% plot. Rate of N use efficiency were 27.4%, 51.2%, 49.0% in paddy field NPK, CRF70% and CRF100% plots respectively. The yield of CRF70% showed the best effect with 9.3% increase production ratio, compare with NPK plot.

• Pediatric Infection and Vaccine
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• v.10 no.1
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• pp.81-86
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• 2003

Purpose : Streptococcus pneumoniae remains a leading cause of meningitis, sepsis, pneumonia, and otitis media in children worldwide. Emergence of drug-resistant organism has substantially complicated the therapy of these infections. This study was conducted to determine the clinical features and changing patterns of antibiotic-resistant rates of Streptococcus pneumoniae. Methods : We have retrospectively examined 306 cases of culture proven patients who were admitted to the Department of Pediatrics, Severance hospital, from the year 1991 to year 2000. The type of culture specimen used, presence of penicillin resistance, characteristics according to various presenting diseases and their prevailing year were also examined. Results : The mean age of cases was 7.9 year and the ratio of male to female was 1.6 : 1. The main age group of pneumococcal infection was under 2 years(42%). Systemic infections associated with pneumococci were sepsis(19.3%) and meningitis(9.5%), while local infections presented as pneumonia(29.2%), otitis media(19.3%), exudative tonsillitis(13.3%), and sinusitis(9.2%) in the order of frequency. Seasonal variation was seen in the incidence of pneumococcal infection: high incidence of infection was seen in Spring(Mar.~Apr; 32%), while the incidence was low during summer(Aug.~Sep.; 6%). Penicillin-resistant rate of pneumococci was steadily on the increase since the year 1991(65%) to year 2000(84%). Conclusion : Antibiotic-resistant pneumococci increased during the past decade. For effective prevention of pneumococcal infections, national survey of pneumococcal infections and expanded use of pneumococcal vaccination would be needed.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.87-94
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• 1985

The seasonal variations of the rate and intensity of metacercarial infection of C. sinensis in P. parva were observed. The fish were collected at Sun-Am River which located in Kim-Hae City, Kyong-Sang Nam Do (=Province), Korea, from March 1983, to February 1984 every month. A total of 788 fish was examined. The number of metacercariae in each fish was individually counted after the individual digestion by artificial gastric juice. The results were as follows: 1. During one year, 513 (65.1%) out of 788 fish were infected with metacercariae. In May, June, July and September, the infection rates ranged from 82.0% to 98.6% whereas the rates was relatively low in March, April, November and February ranging from 11.4% to 64.7%. 2. The intensity of infection was similar with those of infection rates. The mean intensity per infected fish was 103.0 and standard deviation was 118.9 throughout one year. The highest mean intensity was in June (294.8) and the lowest in November (11.1). 3. The observed frequency of fish with certain intensities of metacercariae were fitted to theoretical equations derived from negative binomial distribution in March, April, November and February (p>0.05). Meanwhile, the equation of lognormal distribution were fitted with the observed frequencies in May, June, July and September (p>0.05, p>O. 75). The variance/mean ratio varied by month. The value was the highest in July (814.3) and the lowest in November (158.8). Unlike our hypothesis, the metacercarial density of Clonorchis sinensis in its the most favorable fish host, Pseudorasbora parva showed considerable seasonal variations in the hyperendemic area. The possible factors were discussed.

• Journal of the Korean Arthroscopy Society
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• v.3 no.2
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• pp.115-120
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• 1999

Purpose : After the total or partial meniscectomy of the lateral discoid meniscus, many patients complain the residual pain or the recurrent symptoms of the meniscus, and some of them need reoperation. We analyzed the causes of the reoperation after initial meniscectomy. Material & Method : Two hundred seventy three patients with the symptomatic lateral discoid meniscus were treated by arthroscopic meniscectomy between October, 1989 and September, 1998. Of the 273 patients, 69 patients were treated by total meniscectomy and 204 patients were treated by partial meniscectomy. The male to female sex ratio was 1:1.04, and the average of the age was 23.1 years old(from 4 to 59 years old). The reoperation was done in 8 patients, of which 1 was the case of total meniscectomy at the initial operation, and the rest 7 were the case of partial meniscectomy. Results : Of the 8 reoperations, 3 patients recurred the meniscal symptoms within the 3rd week after the initial operation, and 5 patients recurred beyond the 3rd week after the initial operation. Among the 3 patients of carly recurrence, 2 patients showed inadequate sizes of the remnant meniscus, and 1 patient showed posterolateral instability of the remained meniscus. Among the 5 patients of late recurrence, 3 patients showed rerupture of the meniscus, and 2 patients showed associated pathology of degenerative arthritis following osteochondritis dissecans. Conclusions : The reoperation rate after initial meniscectomy of the lateral discoid meniscus was higher in partial meniscectomy than total meniscectomy. During the operation of the lateral discoid meniscus, we must determine the adequate resectional margin, confirm the remnant meniscus by probing, and look for the associated pathologies.